docs: def value(self):
          """returns object as dictionary"""
          return {
              "type" : "classBreaks",
              "field" : self._field,
              "classificationMethod" : "<classification method>",
              "normalizationType" : self._normalizationType,
              "normalizationField" : self._normalizationField,
              "normalizationTotal" : self._normalizationTotal,
              "defaultSymbol": self._defaultSymbol.value,
              "defaultLabel": self.defaultLabel,
              "backgroundFillSymbol": self._backgroundFillSymbol,
              "minValue" : self._minValue,
              "classBreakInfos" : self.classBreakInfos,
              "rotationType": self._rotationType,
              "rotationExpression": self._rotationExpression
          }